In the construction of metal doors such as, for example, the doors disclosed in U.S. Pat. Nos. 2,297,609, 3,153,817, 3,273,287, 3,333,385, 3,455,078 and 3,750,333, it has been found desirable to provide for a thermal barrier between the sheet metal skins or side panels of the door in addition to providing for a door which is rigid and will remain flat and not warp with changes in temperature and humidity. It is also desirable for a metal door to be constructed so that the hinges may be mounted on either door edge and in a recessed manner so that the hinges are flush with the outer edge surface of the door.
Similarly, it is desirable to provide for mounting the lock or latch bolt on either side of the door for making the door reversible and to position the mounting flange for the bolt housing so that the flange is flush with the corresponding edge surface of the door. In addition to the above features, it is sometimes desirable for the metal door to include an adjustable threshold sealing member along the bottom of the door and to provide for quick and simplified assembly and installation.